Method and apparatus for forcing gas-solid two-phase substance

Abstract

A method and an apparatus for forcing a gas-solid two-phase substance are provided in which the amount of a gas returning to an ordinary-pressure side can be reduced to reduce the consumption of power necessary for gas compression. A solid raw material (a) stored at ordinary pressure is forced into a high-pressure vessel via a switch valve (4) in the following manner. The raw material (a) is accommodated into a rotary valve element (7) disposed in the switch valve (4). Thereafter, an entrained gas (c) present in interstices of raw material (a) is replaced with an incompressible fluid (d).

Description

TECHNICAL FIELD[0001]The present invention relates to a method and an apparatus for forcing a gas-solid two-phase substance in which a solid raw material stored in an ordinary pressure atmosphere is forced into a high-pressure vessel via a switch valve.BACKGROUND ART[0002]In these days, there have been studied natural gas transportation systems for transporting natural gases overseas after artificially hydrating the natural gases. The natural gas transportation system mainly includes steps of generating, pelletizing, transferring, storing, and regasifying natural gas hydrates.[0003]As a main usage of regasified natural gases, conceivable are fuels for power generation and raw materials for town gases. Fuels for power generation require a high pressure of 3.5 MPa or more, and raw materials for town gases require 5.0 MPa or more. An NGH (natural gas hydrate) has such a characteristic that a high-pressure gas is obtained without relying on power machinery, and thus can be subjected to ...

AI Technical Summary

Benefits of technology

[0020]According to the method of the present invention, a gas-solid two-phase substance is forced in the following manner. Specifically, when a solid raw material stored at ordinary pressure is forced into the high-pressure vessel via the switch valve, the raw material is accommodated into the rotary valve element disposed in the switch valve. Thereafter, an entrained gas present in the raw material is replaced with an incompressible fluid. This makes it possible to prevent a high-pressure gas in the high-pressure vessel from flowing into the rotary valve element of the switch valve at the time of feeding out of the raw material. Thus, it becomes possible to prevent the high-pressure gas in the high-pressure vessel from returning to the ordinary-pressure side where a raw material is stored. Moreover, in the method of the invention, since the high-pressure gas in the high-pressure vessel can be prevented from flowing into the rotary valve element of the switch valve as described above, it is no longer necessary to return a gas existing in the switch valve into the high-pressure vessel by using a compressor. This allows reduction in the consumption of power necessary for gas compression.

[0021]Meanwhile, the apparatus of the present invention is an apparatus for forcing a gas-solid two-phase substance in which a solid raw material stored at ordinary pressure is forced into the high-pressure vessel via the switch valve. In the apparatus, the switch valve is formed of: the valve body in the outer shell form; and the rotary valve element which is rotatably provided inside the valve body and which includes the through-hole portion for accommodating the raw material thereinto. In addition, the valve body includes: the raw-material introducing portion; the incompressible-fluid supply portion and the entrained-gas discharge portion for replacing the entrained gas present in the raw material with the incompressible fluid; the raw-material discharge portion for discharging the raw material together with the incompressible fluid to be transferred in the rotary valve element to the high-pressure vessel; the incompressible-fluid discharge portion for discharging the incompressible fluid remaining in the rotary valve element to the outside of the rotary valve element; and the leak-fluid discharge portion for discharging, to an outside of the valve body, the incompressible fluid leaking into the valve body. This makes it possible to prevent the high-pressure gas in the high-pressure vessel from flowing into the rotary valve element of the switch valve at the time of feeding out of the raw material. Thus, it becomes possible to prevent the high-pressure gas in the high-pressure vessel from returning to the ordinary-pressure side where a raw material is stored.

[0022]Moreover, according to the apparatus of the present invention, since the high-pressure gas in the high-pressure vessel can be prevented from flowing into the rotary valve element of the switch valve as described above, it is no longer necessary to return a gas existing in the switch valve into the high-pressure vessel by using a compressor. This allows reduction in the consumption of power necessary for gas compression.

[0023]Moreover, the unit of the present apparatus has a simple structure in which the valve body in the outer shell form and the rotary valve element rotatably provided inside the valve body are formed, and furthermore in which the single through-hole portion for accommodating the raw material is provided in the rotary valve element. Accordingly, the present apparatus has a merit that sealing between the rotary valve element and the valve body is facilitated.

[0024]Furthermore, in the apparatus of the present invention, the perforated plate for preventing outflow of the raw material is provided at least to each of the incompressible-fluid discharge portion and the leak-fluid discharge portion, among the entrained-gas discharge portion, the incompressible-fluid discharge portion, the leak-fluid discharge portion, and the incompressible-fluid supply portion. This makes it possible to prevent outflow of the raw material at the time of switching of the switch valve. Furthermore, in the apparatus of the present invention, the central portion of the through-hole portion has the diameter larger than the diameters of the openings located on both ends of the through-hole portion. Accordingly, the present apparatus has a merit that the amount of the accommodated raw material is increased in comparison with a straight through-hole portion having a constant diameter.

Problems solved by technology

However, it is not easy to continuously introduce NGH pellets stored in an ordinary-pressure atmosphere into a high-pressure regasifying tank.

Moreover, in the case of a rotary feeder system, since a rotor has multiple blades in a radial direction thereof, there is a problem that it is difficult to seal between the rotor and a casing.

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